A serious but under-reported issue regarding water was illustrated by a study which demonstrated the presence of at least 60 known pharmaceuticals in ground water. Of those examined, 30 were found with one or more contaminants occurring in about 80% of the samples. These included: clofibric acid, a cholesterol lowering drug; phenazone and fenofibrate, drugs used to regulate concentrations of lipids in the blood; and analgesics such as ibuprofen and diclofenac1.
In another study, chemotherapy drugs, antibiotics and hormones were found in public drinking water sources2.
In another study by the U.S Geological survey, 25 ground-water and 49 surface-water sources of public drinking water supply in 25 states and Puerto Rico were sampled and analyzed for 124 emerging contaminants. At least one contaminant was detected in 96% of the samples3.
It has been known for over twenty years that pharmaceuticals, personal care products and other organic and inorganic contaminants are being released into the environment, many of which cause ecological and human health risks. In the last ten years, various methods for the analysis of potentially harmful trace environmental contaminants have been developed; however, options for the reduction of environmental exposure, particularly from waste water discharges, have yet to be fully examined. No currently applied or widely used waste water or potable water treatments or filtration systems are able to remove all trace levels of pharmaceuticals and other trace level contaminants. Many nano-filtration or extraction systems that would remove these contaminants are slow, low volume, expensive and often single use.
Thus, there is a need for a filtration method that is inexpensively prepared, as well as one that is simultaneously capable of filtering trace contaminants and large volumes of waters, wastewaters and other solutions. Such a method would enable the user to significantly diminish the contamination in, and thus the environmental impact of, their waste waters. Such a method would also allow a user to greatly reduce the amount of trace level contaminants in ground, surface and potable water supplies once environmental exposure has occurred.
Another issue with currently available commercial filters is that once the filter has reached its expiry or saturation limit, one or more things may occur:                (i) The flow rate of the filtration method is greatly reduced, which may result in damage due to excessive back pressure in the system.        (ii) Reaching the saturation point does not decrease the flow rates but instead increases the flow rates. However, the capacity for the filtration media to remove the desired solutes once at saturation is greatly diminished, meaning that the filtrate may still contains many or all of the undesired components.        (iii) The overused filter may have bacterial or mold growth, and/or may produce water with poor taste, smell and/or color.        
Most often, premature filter changes (changes of filters prior to saturation) are carried out to prevent the above mentioned effects. These may be costly and wasteful if the filters are still usable. For example, waste water volumes may vary seasonally, requiring more frequent changes in summer months and fewer in winter months.
Thus, there is a need for a filtration method that can also incorporate a method for expiry notification. Specifically, if the filtration media used had a detectable color change or voltage change upon saturation, such a change could be used to notify the user that expiration is imminent.